Traditional imaging systems are commonly designed so that the final image quality is high over a narrow region of object space; for example, objects located over a narrow range of object conjugate distances may be imaged by the traditional imaging system to form an in-focus image. The depth of this narrow region of the object space is determined by the depth of field of the system. More recent imaging systems may employ non-traditional imaging designs and techniques that allow an increased depth of field compared to classical systems. For example, U.S. Pat. No. 5,746,371, entitled EXTENDED DEPTH OF FIELD OPTICAL SYSTEMS issued 5 May 1998, discloses imaging systems configured to provide an increased depth of field.
Information that may be present on an object (e.g., a one-dimensional or a two-dimensional bar code) may be readily captured by a variety of conventional systems when the object is motionless, but motion of the object has made capture of the information difficult or impossible. Variables that can affect the ability to capture such information include speed of the moving object, distance of the object from imaging or other systems that are to capture the information, orientation of the information relative to the imaging or other systems, and illumination of the object.